The present invention relates to an apparatus for removing a cylindrical mold, such as a cylindrical rubber molding, sticking to the outer circumferential surface of a mold, and in particular, to a mold removing apparatus wherein all of the steps of removing a molding from a mold are automated, including the delivery of a mold with a molding sticking to it into the mold removing apparatus and the discharge of the mold after removal of the molding from the mold.
As an example, in the process of producing raw edge V-belts, a cylindrical unvulcanized belt material (consisting of rubber, cord, canvas, etc.) wound over a mold is first vulcanized in, for example, a vulcanizer. The mold onto which the vulcanized cylindrical rubber molding (called a slab) is sticking is then removed by a mold removing apparatus to recover the rubber molding product. The conventional mold removing apparatus had the following construction which is illustrated in FIG. 9: a mold removing ring element 61 having a bore slightly larger than to the outer diameter of a mold 62, is placed above the central opening 64 of a frame base 63. The lower end face of a cylindrical rubber molding A sticking to the outer circumferential surface of the mold 62 is placed on the ring element 61 so as to place the cylindrical rubber molding A together with the mold 62 on the ring element 61. A hydraulic cylinder unit 65 is installed above the center of the ring element 61, with the piston rod 66 of the unit 65 being directed downwardly. The piston rod 66 is extended to press down the mold 62 relative to the cylindrical rubber molding A which is held by the ring element 61 to remove the mold 62.
In contrast with the foregoing arrangement, there was another arrangement, not illustrated, wherein a mold is placed in a specified position on the frame base, and a ring element engaging to the top end surface of the cylindrical rubber molding is pressed downwardly by a piston rod of a hydraulic cylinder unit to remove the mold. In either case, the conventional mold removing apparatus used a fixed-shaped ring element 61 matched to the size of the mold 62 to remove the mold 62.
In the case of the above-mentioned conventional mold removing apparatus, however, whenever a mold is changed to a different size, it was necessary to change the ring element to match it with the size of the mold. The change was normally effected by a worker who selected one ring element from a large number of ring elements. Hence the burden on the workers was heavy, and the work efficiency was low since it took much time to change the ring element. Furthermore, since the mold is removed, with the internal circumferential surface of the cylindrical rubber molding closely adhering to the external circumferential surface of the mold, it was necessary to use a very large pressing force (mold removing force) which is exerted by the piston rod of the cylinder unit onto the mold or onto the ring element. Accordingly, the ring element tended to be damaged, and when the mounting of the mold was not appropriate, the mold could be damaged. Due to causes similar to those mentioned above, during removal of the mold, the cylindrical rubber molding tended to become wrinkled or damaged and become useless as a product; consequently, the yield was not satisfactory.
Furthermore, in the case of the conventional mold removing apparatus, the delivery of a mold onto the ring element and the discharge (recovery) of the mold after removal of the molding had to be made by lifting the mold with a crane or the like. It, therefore, was necessary to provide the mold with fittings for hooking hooks, etc. Moreover, the molding from which the mold was removed would remain on the ring element. Handling of the molding and discharge of said mold required manual intervention; thus it was difficult to automatize the operation.